         ! Mesh and Initial condition for  flow over a Half-Cylinder
         implicit none
         integer, parameter:: nx = 128, ny = nx, nz = nx
         real*8, parameter::  PI = 3.1415926535897d0
         integer:: i, j, k
         real*8:: xx(nx), yy(ny), zz(nz), hx
         real*8:: Lref
         !-------------------------------------
         Lref = 1.d-3   ! 1mm
         hx = Lref*2.d0*PI/nx

         do i = 1, nx
            xx(i) = (i - 1.d0)*hx
         end do
         yy = xx
         zz = xx

         open (99, file="OCFD-grid.dat", form="unformatted")
         write (99) xx
         write (99) yy
         write (99) zz
         close (99)
      end

!----------------------------------------------

